This invention relates generally to industrial belts and more particularly to a hinged splice assembly connected between two adjacent industrial belt ends.
Industrial belts of the type to which the present invention relates are generally used in the form of a continuous loop travelling in a circuit around an arrangement of rollers which support the loop. Although endless belts have advantages in durability and wear resistance, they are very difficult and time consuming to install and remove. Accordingly, it is frequently desirable to use industrial belts having two ends which are connected together by a splice. Typically, the splice takes the form of a piano hinge. The splice may be made by machining the ends of a belt to form knuckles having transverse openings which are aligned to receive a pin when the knuckles are intermeshed. The pin holds the ends of the belts together while permitting the belt ends to pivot on the pin relative to one another.
Another common way of forming the splice is by the use of metal hinge splices including a metal splice element securely attached to each end of the belt. The splice elements each have knuckles, and voids sized to receive the knuckles of the splice element on the opposite belt end. Thus the splice elements can be intermeshed and a hinge pin received transversely through the splice elements to form a splice connection. However, the metal hinge splice is a prime site for belt wear and failure.
The present invention has a particular application to industrial belting used to tumble parts being cleaned in an abrasive cleaning machine. Particulate matter (e.g., sand) is thrown, or blown under high pressure against parts in the machine to clean them. As mounted in the abrasive cleaning machine, the industrial belt has a segment forming a cradle in which parts are received. The movement of the belt around its circuit tends to cause the parts to move up the sides of the cradle to a position where the center of gravity of the part is such that it falls back down the side of the cradle in a tumbling fashion. In this way, all sides of the part are exposed to the stream of particulate matter for cleaning.
In the context of abrasive cleaning machines, the industrial belt material has excellent wear resistance so long as the belt is free to deflect under the impact of the particulate matter. However, at certain locations along the belt circuit the belt passes between a pair of opposed rollers defining a nip. The belt is pinched in the nip which causes substantial fatigue in exposed knuckles formed out of the belt material. In addition, small parts being cleaned in the machine and particulate matter can be drawn into the nip by movement of the belt where it is compressed against the belt. Because the belt is held by the opposed rollers and cannot flex, the small part or particulate matter is driven into the belt material causing damage. Thus, it has been found that splices formed by machining piano hinge splice elements out of the belt material at the opposed ends of the belt are subject to significant fatigue and wear at locations which pass through the nip. Damage to the splice can also occur outside the nip under the impact of heavy parts against the splice as they are tumbled by the action of the belt.
Hard material, such as the metal in a metal hinge splice, is more resistant than the belt material to damage caused by the pinching of the belt in the nip and by passage of particulate matter through the nip. However, particulate matter will eventually interpose itself between the hinge pin and knuckles of the splice. Relative movement of the hinge pin and metal splice elements as the belt moves around the turns in its circuit causes substantial wear of the splice elements which can lead to a premature failure of the metal hinge splice.
There is need, therefore, for an industrial belt splice assembly that is easy to install and remove, prevents internal wear of the splice assembly, prevents damage to the parts travelling on the belt by limiting exposure of the parts to the mechanical splice and provides increased wear resistance for increased life and reliability.